Blue markings on Type 4 case

[Willin]

Hi
I have seen several mentions, on these pages, of these blue markings below the serial numbers on type 4 engine cases. I recall someone posted a photo of a brand new (NOS?) case with these marks. And some other pics of the same.
My CB 1700 bus engine has these marks. Something like xx2080xx, or such.
The numbers on my VIN, engine, and trans. all seem to point to originals to my bus. VIN is 223, standard microbus. Late 73 production.
Can I/we assume they are factory marks?
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73 bus. Org. 1700 with dual Weber 40 idfs, bus header with Empi qp muffler, CB magnaspark 2 " ready to run kit".

[Vanapplebomb]

I have seen a lot of them too. No idea what they are for. I have also seen a lot of very small micro stampings as well at various points on cases… almost need a magnifying glass to read those. If you’re not looking, you could easy miss them, but not all cases have them, or some have different markings. Its a mystery, but one I don’t really care about, because I will make whatever I want out of any T4 case.
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1800 Type 4 Berrien 295

http://www.thesamba.com/vw/forum/viewtopic.php?t=487021

[raygreenwood]

are we talking about the rather large blue paint numerals? Post a picture.

I think some of the Euro guys in the 411/412 forum sorted these out about a year ago and they along with the whiteish painted numerals on the sheet metal parts correspond to models/M-code changes/country or delievery options on the assembly line etc.

Yes on the micro-stampings. I have found quite a few of them. They range from numbers, letters to small VW symbols and I believe they are QC stamps from various machining stages.

Ray

[Busstom]

[RWK]

These are off a 1700 EA case I've had for decades, it was a virgin block when I found it, stripped of all externals/tin

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73 Type 181
63 Type 113
63 Type 261- 428 071
62 Type 241-378 025 178 530

[Willin]

Yes, The large blue marks like the second photo RWK posted!
I guess I should have said above the serial number.
I was cleaning my engine to do a top end refresh, when I first got my bus. And I wanted to see what size it was.
I didn't realize the marks were there until they were almost gone. Like RWK's.
I am wondering about the history of my engine. Like I said, I'm sure it's original. I have only pulled the top end. It has VW pistons and cylinders. It is still a 1700. And there was really no wear through out the top end. Perhaps a total of a minute to clean up 4 cylinders with a straight (not ball) style hone. It's all within spec, like end play, ring grooves, rod side clearance, etc. The exhaust valves had been changed out, no sodium valves, and seats cleaned up good. The 1/3 exhaust lobe on the cam has some wear. Stock cam.
I am thinking if the engine was totally rebuilt at some point, those marks would have been gone (?).
I haven't found a reason to split the case. Transmission is good.Bus is really pretty clean.
I know there is a lot of speculation about mileage. My odometer just turned 60,000. I have driven it @ 7000 miles, in 6 years. I am guessing it has turned over once.
I realize I am kind of thinking out loud.
Any thoughts? ( I know someone will say 760,000 miles. )
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73 bus. Org. 1700 with dual Weber 40 idfs, bus header with Empi qp muffler, CB magnaspark 2 " ready to run kit".

[nsracing]

Blue is the warmest color.

[Vanapplebomb]

[Willin]

I guess my question is , will the original pistons and cylinders show very little wear, like they do, at 160000 miles? And the cam? Only one lobe showing significant wear?
When in the past 50 years would VW pistons and cylinders become generally not available? Other than NOS. Now days they all are after market.
Engine had head gasket rings when I pulled the heads. It seems to be a long time ago, when VW said stop using them. I reset deck height to .040 without the HG.
Again, just speculating.
Bus had, what appeared to be , a lot of original ( VW marked) parts. Although I needed to replace most of them.
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73 bus. Org. 1700 with dual Weber 40 idfs, bus header with Empi qp muffler, CB magnaspark 2 " ready to run kit".